Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, a generator, a gearbox, a nacelle, and a rotor having one or more rotor blades. The rotor blades transform wind energy into a mechanical rotational torque that drives one or more generators via the rotor. The generators are sometimes, but not always, rotationally coupled to the rotor through the gearbox. The gearbox steps up the inherently low rotational speed of the rotor for the generator to efficiently convert the rotational mechanical energy to electrical energy, which is fed into a utility grid via at least one electrical connection. Such configurations may also include power converters that are used to convert a frequency of generated electric power to a frequency substantially similar to a utility grid frequency. In addition, the wind turbine typically includes an electrical assembly having one or more electrical cabinets, e.g. the down-tower electrical assembly, that houses the various electrical components of the turbine.
During operation of the wind turbine, high arc flashing can occur in the electrical cabinet(s) during an inside fault event. As used herein, the terms “fault event,” “grid fault,” “fault,” or similar are intended to cover a change in the magnitude of grid voltage for a certain time duration. For example, when a grid fault occurs, voltage in the system can decrease by a significant amount for a short duration (e.g. typically less than 500 milliseconds). In addition, faults may occur for a variety of reasons, including but not limited to a phase conductor being connected to ground (i.e. a ground fault), short circuiting between two or more phase conductors, lightning and/or wind storms, and/or a transmission line being connected to the ground by accident.
During such faults, high energy arc flashing can be experienced in the electrical cabinet(s) of the electrical assembly of the wind turbine. Thus, the arcing energy must either be contained inside of the cabinet(s) or attenuated such that low-level energy is provided at the cabinet exit so as to protect personnel working outside of the cabinet. However, such requirements can be difficult to satisfy since the cabinet(s) also needs to be air-cooled through ventilation and is required to have a certain Ingress Protection (IP) rating, i.e. no or very little water ingress.
Thus, the present disclosure is directed to an improved electrical cabinet wall for an electrical assembly of a wind turbine that addresses the aforementioned issues.